He made loops of blue material along the edge of the end curtain in the first set; he did the same along the edge of the end curtain in the second set.

You are to make loops of blue material along the edge of the end curtain in one set, and in the same way you are to make loops ¹  in the outer edge of the end curtain in the second set.

You are to make fifty loops on the one curtain, and you are to make fifty loops on the end curtain which is on the second set, so that the loops are opposite one to another. ¹ 

He made fifty loops on the first curtain, and he made fifty loops on the end curtain that was in the second set, with the loops opposite one another.

He made fifty loops along the edge of the end curtain in the first set and fifty loops along the edge of the curtain that joined the second set.